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In this week's edition of Tough Call: If 2007 Roger Federer played 2017 Federer on grass, who would win?

Ready, set, go...

4REASONS 2007 FEDERER WOULD WIN

- He was almost invincible on grass: Federer was on a 48-match grass-court winning streak going into the 2007 grass-court season (and it would eventually extend to 65).

- He was actually almost invincible at every major outside of Roland Garros; going into the 2007 grass-court season, he had won nine of the last 10 majors away from Paris.

- Youth: Not many players have defied the aging process like he has over the years, but the Federer from 2007 played—and won—more than the Federer of 2017.

- He was ranked No. 1 in the world (compared to No. 5 in the world now).

4 REASONS 2017 FEDERER WOULD WIN

- He’s kind of forgotten how to lose: Federer’s 19-2 this year, and in the only matches he lost—against Evgeny Donskoy in Dubai and Tommy Haas in Stuttgart—he held match points.

- He doesn’t have any wear and tear from the clay-court season, which he skipped entirely this year— including Roland Garros—to focus on the grass-court season.

- He’ll have more momentum on grass now given there’s a three-week lead-up season.

- Experience: In the last decade he’s not only won eight more majors—bringing his career total to 18—but he’s kept up with, and has continued to lead, an ever-evolving sport.

OUR EXPERTS WEIGH IN

ED MCGROGAN: 2007

In last week's Tough Call, which asked the same question of Rafael Nadal on clay, I included a qualifier that the older version of Rafa could best his younger self under certain conditions. I can’t say the same for Federer, who, aside from the SABR, did everything better and faster in his mid-20s. Federer’s 2007 season began to signal the end of his zenith—remember his back-to-back losses to Guillermo Canas?—but it’s hard to imagine Federer '07 vs. Federer '17 being particularly competitive.

BRAD KALLET: 2007

In July of 2007, Federer captured his fifth consecutive Wimbledon title and was at the peak of his career. He’s had an incredible resurgence in 2017, winning the Australian Open and the Sunshine Double before skipping the clay season, but the fact remains that he’ll soon be 36 and is playing on grass for the first time in just under a year this week. I need to see more from Roger ahead of Wimbledon; on the contrary, I'll never forget how locked in he was in 2007.

NINA PANTIC: 2007

Federer competed in 16 tournaments in 2007 and won half of them, including the Australian Open, Wimbledon and the U.S. Open. Federer in 2017 has been an incredible force, but a fragile, cautious shadow of his older self, picking and choosing his battles with the utmost care. (He wouldn’t dream of skipping the clay season back then.) The younger, fitter and more carefree Federer of yesteryear would come out on top—in a landslide.

STEVE FLINK: 2007

A match on grass between the Roger Federer of 2017 and the Federer of 2007 would be a blockbuster. Federer in 2007 was in the midst of his most dominant stretch, and from 2004-2007 he won 11 of the 16 majors, not losing at Wimbledon in that period. On current form I would give him a decent chance, but I pick the Federer of 2007 to win over the 2017 Roger, 10-8 in the fifth set.

ASHLEY NDEBELE: 2017

2007 Federer was unbeatable on grass, but 2017 Federer is wiser and knows how to maximize his shots. He’s loaded with confidence and is not afraid to attack with his now-potent backhand. Yes, we haven’t seen his grass-court game much yet, but if it’s anything like his 2017 hard-court game, watch out 2007 Federer. Modern Fed doesn’t have vintage Fed’s good knees, but he’s learned how to manage his body and his time, which is a big plus.